The structure of CrAl alloys exhibiting anomalous physical properties

Abstract

An electron diffraction study is made of a quenched Cr—25 at% Al alloy exhibiting anomalous physical properties. An intensive diffuse scattering, complicated in form, with intensity maxima belonging to the ordered β‐phase (Cr2Al) and the recently observed x‐phase is detected. The diffuse scattering, including intensity maxima from the β‐ und x‐phases, is prone to vanish regularly, namely, the zero‐intensity line is always perpendicular to the reciprocal‐space vector, and this indicates that the scattering arises from transversely polarized “soft” modes. An analysis of the reciprocal lattice of CrAl alloys permits the conclusion that the diffraction picture produced by the x‐phase may be described by the incommensurate ω‐phase known in the literature. The detected structure qualitatively explains anomalies in the physical properties of CrAl alloys.

On a computation method for the interpretation of the diffuse scattering from binary solid solutions

“…The last example corresponds to the Cr-A1 system. The diffuse intensities obtained for the composition range from cB = 0.15 to 0.25 are in good agreement with experimental ones observed by den Broeder et al [20], Sudareva et al [21], and Dluzewski [22]. For all these compositions the structure model was generated with the same parameters qi.…”

Structural State of ?-Solid Solution in Quenched Quasicrystal-Forming Alloys of Al61Cu26Fe13

“…Research results [2] show that this phase is featured with a ªdielectricº behavior of the temperature coefficient of resistance and optical conductivity, which has repeatedly been observed earlier for b.c.c. alloys with w-like atomic displacements [12,13].…”

Dynamic phase transformation during superplastic deformation of Nb/Nb3Al in-situ composite

“…[30] The results indicate that the orientation relationship between Nb ss and Nb 3 Al is basically formed between smaller misfit planes, since the {210} planar spacing for Nb 3 Al shows a good fit with the {110} plane of Nb ss . [30] The results indicate that the orientation relationship between Nb ss and Nb 3 Al is basically formed between smaller misfit planes, since the {210} planar spacing for Nb 3 Al shows a good fit with the {110} plane of Nb ss .…”

“…Many dislocations in Nb ss along phase boundaries can be seen. [29,30,31] . However, the two rotational relations about the rotational axis of [ 10] are a few degrees.…”